Leather used in manufacturing products such as leather seats, leather trim and other applications is subjectively graded by visual inspection. Leather “break” is one of the characteristics that are evaluated. Break describes an effect of a loose fiber structure within the leather. Break is manifested on the surface of the leather when it conformed in a concave manner with respect to the top surface (otherwise known as the “grain” surface). The concave conformation is typically achieved by placing the leather, grain side up, into a “half-pipe” or into the cup of your hand. This conformation puts a compressive stress on the grain surface and an expansive stress on the bottom layer (known as the “flesh-side” of the leather). If the fiber structure within the leather is sufficiently loose rather than tightly entwined, the leather will “break” or form pleats on the surface. Leather is graded, in part, based upon the size of the breaks and spacing between breaks in the leather surface. The size of the break is compared to physical standards or photographs of different size break images. Errors in the subjective measurement can lead to customer complaints or reduced yields.
Different areas on a single hide may have different break gradings. For example, the stomach, and neck areas of a hide are sub-prime because they normally have loose fiber structure and larger breaks compared to prime areas such as the back and flanks of the hide. When pieces are cut from the hide by dies, waterjet cutting, or laser cutting, leather parts used in high visibility and high stress areas are cut from prime areas while some leather parts may be cut from areas having larger break ratings. The location and borders of the prime and sub-prime areas varies by age, gender, type of animal, from hide to hide and batch to batch of hides.
Prime areas are conservatively designated to avoid quality issues with some peripheral prime areas not being used for prime parts even though they are of sufficient quality. As a result, maximum utilization of the prime leather of the hides is not achieved and added material cost is incurred.
Hides are inspected and graded upon receipt. Batches having extensive large break areas are rejected or may be accepted with credits based upon the quality of the hide. Visual inspections of the hides are labor intensive and documenting the quality is difficult because of the subjective nature of the inspection process.
This disclosure is directed to solving the above problems and other problems as summarized below.